创建索引

在elasticsearch中创建students索引

  1. PUT /students
  2. {
  3.   "settings": {
  4.     "number_of_shards": 3,
  5.     "number_of_replicas": 2,
  6.     "index.max_ngram_diff":30,
  7.     "analysis": {
  8.       "analyzer": {
  9.         "ngram_analyzer": {
  10.           "tokenizer": "ngram_tokenizer"
  11.         }
  12.       },
  13.       "tokenizer": {
  14.         "ngram_tokenizer": {
  15.           "type": "ngram",
  16.           "min_gram": 1,
  17.           "max_gram": 30,
  18.           "token_chars": [
  19.             "letter",
  20.             "digit"
  21.           ]
  22.         }
  23.       }
  24.     }
  25.   },
  26.   "mappings": {
  27.     "properties": {
  28.       "id": {
  29.         "type": "long"
  30.       },
  31.       "name": {
  32.         "type": "text",
  33.         "analyzer": "ngram_analyzer"
  34.       },
  35.       "gender": {
  36.         "type": "keyword"
  37.       },
  38.       "birthDate": {
  39.         "type": "date",
  40.         "format": "yyyy-MM-dd"
  41.       }
  42.     }
  43.   }
  44. }

创建项目

添加依赖

使用java操作Elasticsearce需要添加spring-boot-starter-data-elasticsearch依赖

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  4.     <modelVersion>4.0.0</modelVersion>
  5.     <parent>
  6.         <groupId>org.springframework.boot</groupId>
  7.         <artifactId>spring-boot-starter-parent</artifactId>
  8.         <version>2.3.2.RELEASE</version>
  9.         <relativePath/> <!-- lookup parent from repository -->
  10.     </parent>
  11.     <groupId>cn.tedu</groupId>
  12.     <artifactId>Elasticsearch</artifactId>
  13.     <version>0.0.1-SNAPSHOT</version>
  14.     <name>Elasticsearch</name>
  15.     <description>Demo project for Spring Boot</description>
  16.     <properties>
  17.         <java.version>1.8</java.version>
  18.     </properties>
  19.     <dependencies>
  20.         <dependency>
  21.             <groupId>org.springframework.boot</groupId>
  22.             <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
  23.         </dependency>
  25.         <dependency>
  26.             <groupId>org.springframework.boot</groupId>
  27.             <artifactId>spring-boot-starter-test</artifactId>
  28.             <scope>test</scope>
  29.         </dependency>
  31.         <dependency>
  32.             <groupId>org.projectlombok</groupId>
  33.             <artifactId>lombok</artifactId>
  34.         </dependency>
  35.     </dependencies>
  37.     <build>
  38.         <plugins>
  39.             <plugin>
  40.                 <groupId>org.springframework.boot</groupId>
  41.                 <artifactId>spring-boot-maven-plugin</artifactId>
  42.                 <version>2.3.2.RELEASE</version>
  43.             </plugin>
  44.         </plugins>
  45.     </build>
  47. </project>

配置yml连接Elasticsearch

  1. spring:
  2.   elasticsearch:
  3.     rest:
  4.       uris:
  5.         - http://192.168.64.181:9200
  6.         - http://192.168.64.181:9201
  7.         - http://192.168.64.181:9202
  8. logging:
  9.   level:
  10.     tracer: trace

创建Student类

  1. @Document(indexName = "students", shards = 3, replicas = 2)
  2. @Data
  3. @NoArgsConstructor
  4. @AllArgsConstructor
  5. @Accessors(chain = true)
  6. public class Student {
  7.     /**
  8.      * 使用学号作为索引id
  9.      */
  10.     @Id
  11.     private Long id;
  12.     private String name;
  13.     private Character gender;
  14.     /**
  15.      * es索引中的字段名,使用Field注解指定,与变量名同名可以省略
  16.      */
  17.     @Field("birthDate")
  18.     private String birthDate;
  19. }

注解及参数说明

  • @Document():标识要持久化到 Elasticsearch 的域对象
    • shards:索引indexName()的分片数。 用于创建索引。默认为1.
    • replicas:索引indexName()的副本数。 用于创建索引。默认为1.
    • `refreshInterval:索引indexName()刷新间隔,默认为1s.
    • indexStoreType:索引indexName()索引存储类型,
    • indexName索引名称，命名要求如下：
      • 仅小写
      • , |, （空格字符）, ,, #/li>
      • 不能以 -、_、+ 开头
      • 不可能是 。 或者 ..
      • 不能超过 255 个字节（注意它是字节，因此多字节字符将更快地计入 255 个限制）
  • @Id:标识该属性为id,在 Elasticsearch 中创建文档时，使用 @Id 注解的字段作为文档的 _id 值
  • @Field:设置字段的数据类型和其他属性。

创建StudentRepository接口继承ElasticsearchRepository接口

Spring Data 的 Repository 接口提供了一种声明式的数据操作规范，无序编写任何代码，只需遵循 Spring Data 的方法定义规范即可完成数据的 CRUD 操作。spring data es repository API只需要定义接口继承ElasticsearchRepository,基础增删改查方法,在父接口中已定义。可以通过继承ElasticsearchRepository接口添加自定义的数据操作方法。

Repository 方法命名规范

https://www.yuque.com/yiquanchaoren-dvwhg/javassm/arwhgdvgif4s?inner=HoIhB

  1. public interface StudentRepository extends ElasticsearchRepository<Student, Long> {
  2.     /**
  3.      * 在name字段搜索关键词
  4.      *
  5.      * @param key 搜索使用的关键词
  6.      * @return {@link List}<{@link Student}> 学生信息列表
  7.      */
  8.     List<Student> findByName(String key);
  10.     /**
  11.      * 在name字段中搜索关键词,或者使用birthDate字段匹配指定日期
  12.      *
  13.      * @param name      名字
  14.      * @param birthDate 出生日期
  15.      * @return {@link List}<{@link Student}> 符合要求的学生信息
  16.      */
  17.     List<Student> findByNameOrBirthDate(String name, String birthDate);
  18. }

进行测试

  1. @SpringBootTest
  2. public class Test01 {
  3.     private final StudentRepository studentRepository;
  5.     @Autowired
  6.     public Test01(StudentRepository studentRepository) {
  7.         this.studentRepository = studentRepository;
  8.     }
  10.     @Test
  11.     public void test1() {
  12.         //在es服务器的students索引中保存学生信息
  13.         studentRepository.save(new Student(1001L, "马大钊", '女', "0659-11-04"));
  14.         studentRepository.save(new Student(1002L, "马二钊", '女', "0659-11-05"));
  15.         studentRepository.save(new Student(1003L, "马三钊", '女', "0659-11-06"));
  16.         studentRepository.save(new Student(1004L, "马四钊", '女', "0659-11-07"));
  17.         studentRepository.save(new Student(1005L, "马五钊", '女', "0659-11-08"));
  18.         studentRepository.save(new Student(1006L, "马六钊", '女', "0659-11-09"));
  19.         studentRepository.save(new Student(1007L, "马七钊", '女', "0659-11-10"));
  20.         studentRepository.save(new Student(1008L, "马小钊", '女', "0659-11-11"));
  21.     }
  23.     @Test
  24.     public void test2() {
  25.         studentRepository.save(new Student(1001L, "马王堆", '?', "0023-11-04"));
  26.     }
  28.     @Test
  29.     public void test3() {
  30.         Optional<Student> stu = studentRepository.findById(1001L);
  31.         //判断Optional对象中是否存在Student对象
  32.         if (stu.isPresent()) {
  33.             System.out.println("-------------------------------" + stu + "---------------------------------");
  34.         }
  35.         Iterable<Student> students = studentRepository.findAll();
  36.         for (Student student : students) {
  37.             System.out.println(student);
  38.         }
  39.     }
  41.     @Test
  42.     public void test4() {
  43.         studentRepository.deleteById(1008L);
  44.     }
  46.     @Test
  47.     public void test5() {
  48.         List<Student> studentList = studentRepository.findByName("马王");
  49.         for (Student student : studentList) {
  50.             System.out.println(student);
  51.         }
  52.     }
  54.     @Test
  55.     public void test6() {
  56.         List<Student> students = studentRepository.findByNameOrBirthDate("堆", "0659-11-05");
  57.         for (Student student : students) {
  58.             System.out.println(student);
  59.         }
  60.     }
  61. }

使用 Criteria 构建自定义查询

Criteria数据查询

  • 使用Criteria封装搜索条件
  • CriteriaQuery封装Criteria条件对象和分页参数
  • 注入ElasticsearchOperations对象进行查询

创建Criteria查询类

  1. @Component
  2. public class StudentSearch {
  3.     private final ElasticsearchOperations operations;
  5.     @Autowired
  6.     public StudentSearch(ElasticsearchOperations operations) {
  7.         this.operations = operations;
  8.     }
  10.     /**
  11.      * 按名称搜索
  12.      *
  13.      * @param key 关键
  14.      * @return {@link List}<{@link Student}> 符合条件的学生列表
  15.      */
  16.     public List<Student> searchByName(String key) {
  17.         Criteria criteria = new Criteria("name");
  18.         //设置条件
  19.         criteria.is(key);
  20.         return exec(criteria);
  21.     }
  23.     private List<Student> exec(Criteria criteria) {
  24.         //将搜索条件封装之Query对象
  25.         CriteriaQuery query = new CriteriaQuery(criteria);
  26.         List<Student> list = new ArrayList<>();
  27.         /*
  28.         使用ElasticsearchOperations工具类执行查询,需要进行依赖注入
  29.         SearchHit对象中包含学生数据,相关度得分
  30.          */
  31.         SearchHits<Student> search = operations.search(query, Student.class);
  32.         for (SearchHit<Student> searchHit : search) {
  33.             Student stu = searchHit.getContent();
  34.             list.add(stu);
  35.         }
  36.         return list;
  37.     }
  39.     /**
  40.      * 根据出生日期进行搜索
  41.      *
  42.      * @param from 开始日期
  43.      * @param to   结束日期
  44.      * @return {@link List}<{@link Student}> 符合条件的学生列表
  45.      */
  46.     public List<Student> searchByBirthDate(String from, String to) {
  47.         Criteria criteria = new Criteria("birthDate");
  48.         criteria.between(from, to);
  49.         return exec(criteria);
  50.     }
  51. }

进行测试

  1. @SpringBootTest
  2. public class Test02 {
  3.     private final StudentSearch search;
  5.     @Autowired
  6.     public Test02(StudentSearch search) {
  7.         this.search = search;
  8.     }
  10.     @Test
  11.     public void test1(){
  12.         List<Student> list = search.searchByName("马");
  13.         for (Student student : list) {
  14.             System.out.println(student);
  15.         }
  16.     }
  18.     @Test
  19.     public void test2(){
  20.         List<Student> list = search.searchByBirthDate("0001-01-01", "2021-11-04");
  21.         for (Student student : list) {
  22.             System.out.println(student);
  23.         }
  24.     }
  25. }

Criteria分页查询和高亮

分页

  • Pageable—-向服务器提交的分页参数，page(页数),size(每页的记录数)
  • Page ————从服务器返回的一页数据，数据列表，分页信息（可选，可直接使用List<?>）

  • Repository 

    1. Page<Student> findByName(String key, Pageable pageable);

  • Criteria 

    1. Criteria criteria = new Criteria(args);
    2. CriteriaQuery query = new CriteriaQuery(criteria);
    3. query.setPageable(pageable);

创建接口

  1. public interface StudentRepository extends ElasticsearchRepository<Student, Long> {
  2.     /**
  3.      * 在name字段中搜索关键词,或者使用birthDate字段匹配指定日期进行分页查询
  4.      *
  5.      * @param name      名字
  6.      * @param birthDate 出生日期
  7.      * @param pageable  分页参数
  8.      * @return {@link List}<{@link Student}>
  9.      */
  10.     Page<Student> findByNameOrBirthDate(String name, String birthDate, Pageable pageable);
  11. }

进行测试

  1. @SpringBootTest
  2. public class Test01 {
  3.     private final StudentRepository studentRepository;
  5.     @Autowired
  6.     public Test01(StudentRepository studentRepository) {
  7.         this.studentRepository = studentRepository;
  8.     }
  10.     @Test
  11.     public void test7() {
  12.         Pageable pageable = PageRequest.of(1, 2);
  13.         Page<Student> students = studentRepository.findByNameOrBirthDate("马", "0659-11-05", pageable);
  14.         System.out.println("共有几页:" + students.getTotalPages());
  15.         System.out.println("是否有上一页:" + students.hasPrevious());
  16.         System.out.println("是否有下一页:" + students.hasNext());
  17.         System.out.println("每页大小:" + students.getNumber());
  18.         for (Student student : students) {
  19.             System.out.println(student);
  20.         }
  21.     }
  22. }